Adobe stabilized
Introduction
Cement soil or cement-stabilized soil is a dry mixture of soil or earth with certain granulometric characteristics, Portland cement and, where appropriate, additives. A certain amount of water is added to the mixture for setting and it is subsequently compacted.
Typically, the percentage of Portland cement can vary between 7 to 12% depending on the type of soil.
Certain conditions of insusceptibility to water (impermeability, insolubility), resistance, durability and appearance are required for the already cured or set product.
Construction methods
Two construction methods are distinguished, depending on the place where the soil-cement mixture is carried out:
Since it is common to use soil-cement in small self-construction works or in constructions for social purposes, we will limit ourselves to this.
There are large works built with soil-cement, such as the Urugua-í Dam in the Province of Misiones, Argentina; although its use is less frequent.
Mixing characteristics
The cement soil is a mixture of sifted earth (approximately half a cm mesh), common sand and Portland cement, so that the volumetric ratio between the first two is 2:1.
Cement dosages are calculated as a percentage by weight of the dry material.
Soil moisture during tamping can be 18% wet basis.
Granulometry[1]
Granulometry defines the different particle sizes of a soil, expressed as a percentage in relation to the total size of a sample. The size of the particles that make up the mixture is important since it directly influences porosity, water absorption and durability. An adequate distribution of particle sizes is known as a well-graded soil, and allows obtaining greater compressive strength in pieces made with these characteristics.
The smaller the number of empty spaces, the porosity is reduced and the resistance to water and mechanical stress is increased, since the gaps left by the large particles are filled by the medium ones and so on, generating greater contact between particles, which causes an improved volumetric weight and resistance to compression. In this way, an ideal granulometry must include particles of different sizes and this is achieved by knowing the quantitative distribution of the sizes of the particles of a soil.